218 research outputs found

    Exergy cost assessment of solar trigeneration plant based on a concentrated solar power plant as the prime mover

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    An exergy cost assessment of solar trigeneration plant to generate electricity, fresh-water, and heat is carried out in order to study the process of exergy cost formation, to determine the key components that contribute to the cost of each product, and to establish the best configuration in term of unit exergy cost. The solar trigeneration plants evaluated consist of a concentrated solar power (CSP), a multi-effect distillation plant, and a process heat module, in which the CSP plant is the prime mover. The methodology includes modeling and evaluating the performance of standalone and trigeneration plants using the symbolic exergoeconomic methodology. Results show that the best configuration, in terms of exergy cost, is when the multi-effect distillation plant replaces the power cycle condenser. Regarding the costs formation, the key components which could be improved in their design are: solar collectors, evaporator, re-heater, dissipative systems, and productive subsystems

    Preparation and characterization of polymeric microspheres for Cr(VI) extraction

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    Microspheres (MS) from different polymers were prepared using two routes. Route A: process of phase inversion with solutions of polysulfone (PSf) in dichloromethane (DCM) and polyvinylpyrrolidone (PVP) as additive. Different weight ratios of PSf-PVP were used in the MS preparation. Route B: MS were obtained by cross-linking in emulsion using a commercial silicone as raw material. The obtained MS were analysed according to their morphological-structural characteristics and in relation to their Cr(VI) extraction capacity using impregnated MS with Aliquat 336. The results obtained showed that MS prepared with PSf-PVP have both less specific surfaces and relative porosities when the proportion of PVP in the mixture is increased. Extraction tests of ion Cr(VI) indicated that synthesized MS have adequate structural characteristics and interesting adsorptive properties which give rise to impregnating selective extractants. Impregnated microspheres with Aliquat 336 prepared from 2:1 PSf-PVP ratio achieved the highest Cr(VI) extractive performance (92% of Cr extraction for contact time of 60 min) and the best breakthrough point in column tests (up to 10 h in the first cycle).Fil: Ochoa, Nelio Ariel. Universidad Nacional de San Luis. Facultad de Ciencias Fisico Matematicas y Naturales. Departamento de Fisica. Laboratorio de Ciencias de Superficies y Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Illanes, Cristian Omar. Universidad Nacional de San Luis. Facultad de Ciencias Fisico Matematicas y Naturales. Departamento de Fisica. Laboratorio de Ciencias de Superficies y Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Marchese, Jose. Universidad Nacional de San Luis. Facultad de Ciencias Fisico Matematicas y Naturales. Departamento de Fisica. Laboratorio de Ciencias de Superficies y Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Basualto, C.. Universidad de Chile; ChileFil: Valenzuela, Fernando R.. Universidad de Chile; Chil

    Tratamiento estadístico de datos meteorológicos en Villa Unión, Dpto. Cnel. F. Varela La Rioja, periodo junio 2010-julio 2011.

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    This study assessed the climatic data for meteorological stations and rainfall of the study area were obtained monthly mean precipitation and annual average methods: arithmetic and Thiessen polygons by drawing isohyets, average temperatures, maximum and monthly minimum, values of humidity, wind speed and atmospheric pressure, as well as agro-meteorological data, for the period July 2010 - June 2011.Astation in El Molle and one in Los Palacios, and two digital gauges for the Banda Florida district and Guillermo Paez.En este trabajo se evaluaron los datos climáticos correspondientes a las estaciones meteorológicas y pluviométricas de la zona de estudio y se obtuvieron las precipitaciones medias mensuales y medias anuales por los métodos: aritmético, polígonos de Thiessen y mediante el trazado de isoyetas; temperaturas medias, máximas y mínimas mensuales; valores de humedad; velocidad del viento y presión atmosférica, además de datos agrometeorológicos, correspondientes al periodo julio 2010-junio 2011. Una estación en la localidad de El Molle y otra en la localidad de Los Palacios, y dos pluviómetros digitales correspondientes a la localidad de Banda Florida y el barrio de Guillermo Páez

    Caracterización mediante simulación de sistemas fotovoltaicos para riegos agricolas y análisis de su rentabilidad económica

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    CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: Este trabajo presenta un modelo desarrollado con la herramienta Simulink de Matlab de un sistema fotovoltaico de bombeo para riego agrícola. El modelo se ha aplicado en la simulación de los sistemas de riego de una finca típica de 20 ha en varios lugares. A partir de los resultados de la simulación se ha realizado el análisis económico de los sistemas fotovoltaicos necesarios. Se puede concluir que el modelo desarrollado caracteriza con éxito el funcionamiento de los sistemas fotovoltaicos. Los resultados del análisis económico muestran que la energía fotovoltaica permite una reducción de costes de la energía eléctrica utilizada por los agricultores.ABSTRACT: A photovoltaic pumping system for irrigation in agriculture has been modelled using Matlab’s Simulink. The model has been applied to simulate the irrigation systems of a typical 20 ha farm in various locations. From the results of the simulation, the economic analysis of the required photovoltaic systems has been carried out. It can be concluded that the developed model successfully characterizes the operation of the photovoltaic systems. The results of the economic analysis show that photovoltaic energy lets a cost reduction of the electric power used by farmers.info:eu-repo/semantics/publishedVersio

    Evaluación comparativa de 19 modelos de estimación de irradiancia difusa sobre planos inclinados dependiendo del tipo de cielo estándar ISO/CIE

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    CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: En este trabajo se han evaluado 19 modelos de estimación de irradiancia difusa sobre el plano inclinado, que incluyen tanto modelos isotrópicos o pseudoisotrópicos como modelos anisotrópicos. Dicha evaluación se ha llevado a cabo a partir una serie de 5396 observaciones de irradiancia global, difusa y directa realizadas entre julio y diciembre de 2018 en la estación radiométrica de la Universidad Pública de Navarra (UPNA). El estado del cielo correspondiente a cada observación se ha caracterizado de acuerdo con el CIE Standard General Sky propuesto en la norma ISO 15469:2004(E)/CIE S 011/E:2003. Para esta clasificación se han utilizado las medidas de distribución angular de luminancia y radiancia proporcionadas por un escáner de cielo ubicado en la propia estación de la UPNA. De tal manera que, para cada combinación de orientación e inclinación del plano, se ha evaluado la bondad de los distintos modelos de acuerdo con los 15 tipos de cielo estándar propuestos por la norma ISO/CIE. Los resultados revelan que el modelo de Perez et al. 2 presenta los mejores resultados globales, así como en 5 de los 15 tipos de cielo ISO/CIE.ABSTRACT: A total of 19 models for estimating diffuse irradiance on the inclined plane have been evaluated in this work, which include both isotropic or pseudoisotropic models and anisotropic models. This evaluation has been carried out from a series of 5,396 measurements of global, diffuse and direct irradiance carried out between July and December 2018 at the radiometric station of the Public University of Navarra (UPNA). The sky conditions corresponding to each observation has been characterized according to the CIE Standard General Sky proposed in the standard ISO 15469:2004(E)/CIE S 011/E:2003. For this classification, the angular distribution of luminance and radiance measurements provided by a sky scanner located at the UPNA station have been used. In such a way that, for each combination of plane’s orientation and inclination, the goodness of the different models has been evaluated in accordance with the 15 standard sky types proposed by the ISO/CIE standard. The results reveal that the Perez et al. 2 model shows the best overall results and for 5 of the 15 ISO/CIE standard sky types.info:eu-repo/semantics/publishedVersio

    Wax worm saliva and the enzymes therein are the key to polyethylene degradation by Galleria mellonella

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    Plastic degradation by biological systems with re-utilization of the by-products could be a future solution to the global threat of plastic waste accumulation. Here, we report that the saliva of Galleria mellonella larvae (wax worms) is capable of oxidizing and depolymerizing polyethylene (PE), one of the most produced and sturdy polyolefin-derived plastics. This effect is achieved after a few hours’ exposure at room temperature under physiological conditions (neutral pH). The wax worm saliva can overcome the bottleneck step in PE biodegradation, namely the initial oxidation step. Within the saliva, we identify two enzymes, belonging to the phenol oxidase family, that can reproduce the same effect. To the best of our knowledge, these enzymes are the first animal enzymes with this capability, opening the way to potential solutions for plastic waste management through bio-recycling/up-cycling
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